Soldato
It annoys the hell out of me as well, I parked at a local Asda, quite early and there were whole rows of empty spaces so I parked up as the only car in the row. Then just as we were getting our trolley I looked over as a woman parked right next to me. I considered saying something but then had a better idea. I went & moved my car so close she would be unable to even get to her door. I was still within the lines as well as I'd parked a bit haphazard as the place was so empty. Then we went in the store and I watched the woman while the wife did some shopping. Then I saw her head for the checkout I watched as she headed out to the car park. She didn't actually notice that she could not get in until she put her shopping in the boot.
Then she stood there looking frustrated and fetched the trolley pusher bloke to have a look. so I went over and asked what was going on, she claimed some idiot had parked right next to her car even though the car park was empty! so I said well no actually the red Toyota was here first and if so why did you feel the need to park right next to it when the car park is completely empty? She claimed her driving instructor taught her that way, to always park neatly etc but there was definitely no other car when she parked. So I pointed to a previous ding in my door, see that? people like you did that for no good reason. She just huffed and showed signs of getting upset so I let it go and moved my car and she sped off lesson learned hopefully.
Sorry, I'd have been determined to get back in my car if I were her. Using the doors you had parked near.